Small enough that two people standing inside it would fill most of the floor space, it measures roughly four metres by three metres internally, its curved side formed by drystone walling still standing to about eighty centimetres in height. The straight edge of the D is provided by the cashel wall itself, a practical arrangement that saved labour and material by borrowing an existing boundary as one full side of the shelter.

A cashel is a roughly circular or oval enclosure defined by a stone wall, a form of defended or demarcated farmstead common across early medieval Ireland. The cashel at Clooneen is described as large and suboval, and this hut site sits within it, pressed close to the interior of the perimeter. That positioning is telling. Huts built against the inner face of a cashel wall were a recurring feature of these enclosures, making use of the shelter and structural solidity the outer wall provided. The drystone construction, in which stones are laid without mortar and rely on careful placement and their own weight for stability, is consistent with the kind of vernacular building tradition associated with early Irish settlement sites. The fact that the walling survives to any appreciable height at all, given the centuries of weathering and agricultural disturbance that affect so many sites of this type, is itself worth noting.